TWI694104B - Antioxidant stabilizer for polymers and preparation method of stabilizer - Google Patents

Abstract

A stabiliser for an organic polymer comprising a) poly (dicyclopentadiene-co-p-cresol) (Formula 1); b) a sterically hindered phenol of Formula II; and c) an alkyl thio methyl phenol of Formula III.

Description

Antioxidant stabilizer for polymers and preparation method of stabilizer

The present invention relates to compositions that are beneficial for stabilizing organic polymers, especially natural or synthetic rubbers and other elastomers, to prevent their oxidative degradation and decay. The invention also relates to methods for preparing aqueous dispersions of these compositions and their use in stabilizing polymers.

Synthetic rubber is an elastomer that can be made by a water-based process in which monomers are polymerized by free radical emulsion polymerization in the presence of surfactants. The resulting emulsion contains an aqueous dispersion of polymer particles. These particles can be coagulated, separated from water and then dried to form a solid rubber or be kept in its emulsion form for application. Because natural and synthetic elastomers containing unsaturated monomers are inherently sensitive to oxidative degradation, it is routine to add one or more antioxidants to them.

The aging of an organic polymer or its sulfide can cause changes in various properties, such as an increase in the hardness or brittleness of the polymer. Or, softening, loss of elastomer properties, or loss of mechanical strength may occur. Cracking, surface changes, or other changes such as electrical properties may be observed. Undesirable odors and discoloration often occur.

To prevent or slow down this aging process, it is known to add antioxidant compounds. These can be classified into four main categories: (i) mono- or low-functional secondary aromatic amines; (ii) mono- or low-functional substituted phenols; (iii) heterocyclic compounds containing mercapto groups, and thioesters; and ( iv) Phosphite

When the polymer or sulfide to be protected is exposed to higher temperatures, especially for a longer period of time, the effectiveness of the anti-aging compound is usually slowed down. Ideally, these anti-aging compounds do not have a coloring effect, but provide good color stability to the rubber or its sulfide and can be used in combination with peroxides or sulfur-based vulcanizing agents. Some known anti-aging compounds are toxic. In addition to diphenylamine, phenolic antioxidants are also toxic. For example, Vulkanox ^® BKF is classified as H361f and is suspected of damaging fertility.

Due to the increasing demand for storage stability and color stability of rubber and its sulfides, especially when exposed to high temperatures, it provides novel and improved methods for preventing and slowing down the aging process of rubber and sulfides The concept is a continuous task. This includes minimizing the necessary amount of anti-aging compounds without reducing the stabilizing effect.

Examples of rubbers that can be stabilized according to the invention are: NBR nitrile rubber as defined in more detail below, HNBR partially or fully hydrogenated nitrile rubber as defined in more detail below, SBR styrene-butadiene copolymerization Substances, including its carboxylated derivatives, CR polychloroprene, BR polybutadiene, IIR isobutene-isoprene copolymer, the content of isoprene by weight is preferably 0.5% to 10%, BIIR Brominated isobutylene-isoprene copolymer, the content of bromine by weight is preferably 0.1% to 10%, CIIR chlorinated isobutylene-isoprene copolymer, the content of chlorine by weight is preferably 0.1% to 10%, ABR butadiene-C _1-4 -alkyl acrylate copolymer, NIR acrylonitrile isoprene rubber

SIR Styrene Isoprene Rubber

IR polyisoprene rubber, NR natural rubber

ENR Epoxidized natural rubber, or a mixture thereof.

For example, storage and color stability of nitrile rubber, styrene-butadiene rubber ("SBR") or other types of rubber are frequent problems. For the purpose of this article, storage stability means that the change in Mooney viscosity is as small as possible during long-lasting storage, especially at high temperatures; and color stability means that the rubber shows the basis after storage at high temperatures The value of ΔE determined by the CIEDE 2000 color difference formula is as small as possible.

For elastomers manufactured using water-based processes, it is highly desirable to add an aqueous dispersion of antioxidants to the rubber emulsion. This is to ensure the most effective and efficient incorporation of antioxidants into the final polymer. The currently used antioxidant system contains a single phenolic antioxidant or a combination of a phenolic antioxidant and a thioester antioxidant. A commonly used phenolic antioxidant is commonly known as the L-type antioxidant (commercially available in Wingstay L, Lowinox CPL and Ionol LC under the trade name) of butylated reaction products of p-cresol and dicyclopentadiene (CAS 68610-51-5), either alone or with, for example, dilauryl thiodipropionate (CAS 123- The thioester combination of 28-4) has been used as a dispersion. In addition, 4,6-bis(octylthiomethyl)-o-cresol (CAS 110553-27-0), commonly known as antioxidant 1520, has also been combined with phosphite antioxidants, such as the three commonly known as TNPP Nonylphenyl phosphite (CAS 26523-78-4) was used. Another commonly used antioxidant is 2,2'-methylenebis(6-tert-butyl-4-methylphenol) (CAS 119-47-1); commonly referred to as antioxidant 2246, which has Health and safety hazards of health (risk term R61).

There is an uninterrupted need to improve the protection of these polymers and prevent their oxidative degradation, because this degradation has a deleterious effect on aesthetics and mechanical properties. There is also a need to address health and safety hazards involving some currently available antioxidant technologies.

WO-A-2001/081458 discloses a stabilizing mixture for mixing two sterically hindered phenolic esters, which is kept in a liquid state after being heated together, so that it can be used to stabilize solid rubber. Because the antioxidant mixture is not fully compatible with aqueous polymers, the use of this formulation to stabilize aqueous polymer dispersions is inherently inefficient.

EP-A-0 488 550 describes a stabilizer composition comprising 1) a sulfide having one or more sulfur-containing groups -CH ₂ -S-CH ₂ -R, where R is a C ₁ -C ₂₀ alkane Group or alkyl alkanoate or 2,4-bis(n-octylthio)-6-4'-hydroxy-3',5'-di-tert-butylanilinyl) 1,3,5-triazine, And at least two sterically hindered phenols (2) and (3), one of which (3) is less sterically hindered than the other (2). These compositions can be incorporated into polymers to become polymer additives. These polymer additives can provide polymer products with improved physical and mechanical properties. They are used at high concentrations of 1% to 4% by weight of the polymer, and the focus is on stabilizing acrylate-based rubbers. Its use shows some synergistic effects, however, neither shows the stability of the rubber molecular weight increase, nor does it disclose or teach how to reduce the amount of the stabilization system.

US-A-5,116,534 discloses a combination of (i) a phenolic antioxidant, (ii) a thiodipropionate, and (iii) a phosphite. It emphasizes alkyl-substituted phenyl phosphites such as TNPP (trinonylphenyl phosphite). Nowadays, these phosphites are considered harmful in view of their toxic by-products, especially nonylphenol. US-A-5,116,534 does not disclose whether these stabilizers are suitable for increasing the color stability of polymers.

的硫基團的空間位阻酚，其中R₁ 為C₈-C₁₂烷基 WO-A-2009/138342 discloses a combination of the following (a) and (b): a) contains at least one of the following chemical formula

Sterically hindered phenol of sulfur group, where R ₁ is C ₈ -C ₁₂ alkyl

R ₂ is hydrogen, C ₁ -C ₁₂ alkyl, cyclohexyl, 1-methylcyclohexyl, benzyl, α-methylbenzyl, α,α-dimethylbenzyl or -CH ₂ -SR ₁

R ₃ is C ₁ -C ₁₂ alkyl, benzyl, α-methylbenzyl, α,α-dimethylbenzyl or -CH ₂ -SR ₁ , and R ₄ is hydrogen or methyl, and b )Styrenated diphenylamine of the following formula

It is used to stabilize emulsion polymers or rubber latex. However, diphenylamine is toxic.

EP-A-0 439 427 describes an aqueous emulsion which contains at least: (A) a phenolic antioxidant and/or (B) thiodipropionate and/or (C) an organic phosphite; a surface active Agent, which is a salt of an organic acid; and an alcohol.

其中n為1至10，

及c)一種不同於式(II)的硫醚。 WO2005/023886 discloses a method for stabilizing a) methyl methacrylate-butadiene polymer styrene graft polymer, which uses b) a sterically hindered phenolic antioxidant, the chemical formula of which is (I ), formula (II) or formula (III) or mixtures thereof

Where n is 1 to 10,

And c) a thioether different from formula (II).

WO-A-2002/14419 discloses sterically hindered phenol salts for stabilizing rubber. These stabilizers are characterized by containing at least two phenolic hydroxyl groups. Preferred sterically hindered phenolic compounds are those of the following formula

Wherein R ¹ , R ² and R ³ may be the same or different, R ¹ and R ² are C ₁ -C ₁₂ alkyl or C ₅ -C ₈ cycloalkyl and R ³ is hydrogen, C ₁ -C ₈ alkyl Or C ₅ -C ₆ cycloalkyl. However, there is no disclosure related to the improvement of stabilization efficiency through the combination of specific stabilizers.

的酯或酯的混合物組成，其中R₁及R₂相同或不同，表示一種線性的或分枝的C₁-C₁₈烷基基團；R₃表示一種線性的或分枝的C₈-C₁₈烷基基團或下述基團之一：

CH₃-(CH₂)_p-CH₂-其中m和n各自為由0至11、包括0和11的整數、m+n為10或11，而p 為12或13；b)一種具有下式

的屬於空間位阻酚的群組的固態化合物， 其中n為一個在由0至10的範圍內、包括0和10的整數。 WO-A-2001/081458 discloses a mixture for liquid stabilization of organic polymers, which contains: a) a liquid compound belonging to the group of sterically hindered phenols, which has the general formula (I)

The ester or mixture of esters, where R ₁ and R _{2 are the} same or different, represent a linear or branched C ₁ -C ₁₈ alkyl group; R ₃ represents a linear or branched C ₈ -C ₁₈ alkyl group or one of the following groups:

CH ₃ -(CH ₂ ) _p -CH ₂ -where m and n are each an integer from 0 to 11, including 0 and 11, m+n is 10 or 11, and p is 12 or 13; b) one has the following formula

Of solid compounds belonging to the group of sterically hindered phenols, where n is an integer ranging from 0 to 10, inclusive.

The stabilizing mixture is said to be liquid and prepared by heating the ingredients together. The inherent problem associated with this mixture is insufficient compatibility with aqueous polymer dispersions. It is disclosed in WO-A-2001/81458 that such a mixture can be used in combination with more stabilizers and lists many types of compounds. There is no disclosure of any specific stabilizer combination that may have a synergistic effect to enhance the stabilizing effect on rubber.

In summary, it can be said that there is no description of a non-toxic stabilizing system that improves the stability of Mooney viscosity of rubber.

Therefore, the object of the present invention is to provide a stabilizer that gives unsaturated rubber good storage stability in terms of Mooney viscosity and color stability, does not contain toxic or environmentally hazardous compounds, and at the same time provides good vulcanization characteristics and Favorable mechanical properties.

According to a first aspect of the invention, a stabilizer for an organic polymer mixture comprises one or more compounds from group (a), one or more compounds from group (b), and one or more compounds from group The compound of (c), wherein (a), (b) and (c) are as follows: (a) a copolymer of p-cresol and dicyclopentadiene of formula I;

Where n is an integer in the range from 1 to 10, (b) a sterically hindered phenol of formula II; and

Wherein R ¹ is a hydrogen group; linear or branched, saturated or unit or polyunsaturated, unsubstituted or substituted alkyl; saturated or unit or polyunsaturated carbocyclic or heterocyclic group Aryl; heteroaryl, arylalkyl, heteroarylalkyl, preferably polyoxyalkylene ether of polyoxyethylene ether or polyoxypropylene ether or polyoxyethylene polyoxypropylene ether; and R ² are the same Or different and represents a linear or branched C ₁ -C ₆ alkyl or C ₅ -C ₆ cycloalkyl; and (c) an alkylthiomethylphenol antioxidant of formula III:

R ³ is a linear or branched C ₁ -C ₁₄ alkyl group; and R ⁴ is a hydrogen group, a linear or branched, saturated or unit or polyunsaturated, unsubstituted or substituted alkane Group; saturated or unit or polyunsaturated carbocyclic or heterocyclic group; aryl; heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, Alkylthio or arylthio.

In a preferred formulation, the phosphite antioxidant (if present) is selected from the group consisting of (d): tri(nonylphenyl) phosphite; tri(2,4-di-tert-butylphenyl) Phosphite; other alkylaryl phosphites and their mixtures.

The present invention provides a combination of an antioxidant aqueous dispersion and an antioxidant, which can improve the aesthetic and mechanical properties of the polymer compared to those obtained using currently available technologies.

The stabilizer may comprise a mixture of a compound selected from each group including (a), (b) and (c) and an optional compound selected from group (d).

Alternatively, two or more compounds can be selected from each of one or more of the groups (a), (b), and (c) and a single compound can be selected from the remaining groups.

Particularly advantageous stabilizers comprise two or more compounds selected from groups (a), (b) and (c).

In a preferred composition, the weight ratio of (a):(b):(c) is in the range of 1 to 100:30:1 to 100.

The ratio is preferably 5 to 30: 5 to 30: 5 to 30.

The ratio is more preferably 5 to 30:10:5 to 30.

The best ratio is 10:10:10.

Another optimal ratio is 20:10:20.

When compound (d) is present, the amount thereof is 1-50% of the total mass of the antioxidant, more preferably 5-30% of the total mass of the antioxidant.

According to a second aspect of the invention, a stabilizer for an organic polymer mixture comprises one or more compounds selected from group (a) as defined above and one or more compounds selected from group (c) as defined above A mixture of compounds.

In a particularly preferred embodiment, the stabilizer comprises a single compound selected from group (a) and a single compound selected from group (c).

The stabilizer according to the second aspect preferably comprises a compound selected from groups (a) and (c), which is intended to be free of more antioxidants.

In a preferred composition, the weight ratio of (a):(c) is in the range of about 4:1 to about 1:1, preferably about 3:1 to about 1:1, more preferably about 2:1 to about 1:1.

Alternatively, the range of (a): (c) is 3:2 to 2:4, preferably 3:2 to 2:3. A particularly advantageous composition has a ratio of 1:1.

According to a third aspect of the invention, a stabilizer for an organic polymer mixture comprises one or more compounds selected from group (b) as defined above and one or more compounds selected from group (c) as defined above A mixture of compounds.

In a particularly preferred embodiment, the stabilizer comprises a single compound selected from group (b) and a single compound selected from group (c).

The stabilizer according to the second aspect preferably comprises a compound selected from groups (b) and (c), which is intended to be free of more antioxidants.

In a preferred composition, the weight ratio of (b):(c) is in the range of about 4:1 to about 1:1, preferably about 3:1 to about 1:1, more preferably about 2:1 to about 1:1, especially about 1:1.

In the preferred embodiment, the smallest amount of component (c) is used.

The composition according to the second and third aspects of the present invention has the advantage of making the stabilized rubber whiter and better preserved.

According to the fourth aspect of the present invention, the preparation method of the stabilizer according to the aforementioned aspect of the present invention comprises the following steps: For the group selected from group (a), (b), (c) and optional group (d) A mixture of the compounds is heated to a temperature above 60°C to form a molten mixture; adding a surfactant to the molten mixture; adding hot water to the molten mixture; stirring the aqueous mixture; and optionally adding one or more Further raw materials.

A specific example of this ingredient (a) is commonly referred to as L-type antioxidant. This compound has CAS 68610-51-5.

A particularly preferred compound from group (b) is octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, which is commonly referred to as antioxidant 1076. This compound has CAS 2082-79-3.

A particularly preferred compound is 2-methyl-4,6-bis(octylthiomethyl)-phenol, which is usually Called antioxidant 1520. This compound has CAS 110553-27-0.

In an advantageous embodiment of the invention, the antioxidant is a mixture of L-type antioxidant, antioxidant 1076 and antioxidant 1520.

In a further embodiment, the antioxidant mixture may also consist of any two of these antioxidants and optionally a phosphite of formula IV.

When two antioxidants are used, a preferred combination is component (a) and component (c).

More preferably, one of the antioxidants is an L-type antioxidant, and the best is that the L-type antioxidant is combined with antioxidant 1520, with or without the addition of further antioxidants (b) and (d).

The phosphite antioxidant (d) preferably comprises one or more phosphites selected from the group consisting of: tri(nonylphenyl) phosphite; (TNPP), tri; tri(2,4- Di-tert-butylphenyl) phosphite; or a phosphite sold under the Weston 705 trademark (Addivant USA LLC)

The composition may further include one or more additional antioxidants or synergists. Preferred additional antioxidants or synergists are selected from the group consisting of tocopherols, phenolic aldehydes, thioesters, phosphates, triazines, amines, benzyl compounds and ascorbic acid. Other additives, such as light stabilizers, catalysts and brighteners, can also be mixed with these antioxidants and synergists.

In conventional industrial practice, it is desirable to use an aqueous dispersion of the above composition to maximize compatibility and incorporation efficiency. A dispersion can be defined as a heterogeneous mixture of organic substances suspended in water. To provide these, more raw materials may be needed, the raw materials containing one or more of the following: water, Surfactants, thickeners, preservatives and adjuvants such as anti-foaming agents.

Surfactants can be anionic, nonionic, or cationic in nature. A preferred surfactant may comprise a mixture of a fatty acid such as oleic acid and a base such as an aqueous solution of potassium hydroxide.

A preferred thickener may be an aqueous gum, preferably xanthan gum. It is better to ensure long-term stability during storage and transportation.

Alternatively, solutions of these mixtures in water or organic solvents can be used.

A stabilizer dispersion of the present invention can be produced by heating and mixing these molten raw materials. A surfactant can be added. A suitable surfactant may comprise a mixture of long-chain aliphatic acids such as oleic acid and bases such as aqueous potassium hydroxide. The resulting mixture can be stirred with hot water and an aqueous gum such as xanthan gum to form a suspension, which can be cooled. Any further raw materials such as biocides can be added before packaging and storage or distribution.

The stabilizer of the present invention can be used to stabilize a wide range of rubbers and other polymer materials, including: nitrile rubber; partially or fully hydrogenated nitrile rubber; styrene-butadiene copolymer, including its carboxylated derivatives Polychloroprene; polybutadiene; isobutylene-isoprene copolymer; brominated isobutylene-isoprene copolymer; chlorinated isobutylene-isoprene copolymer; butadiene-C _{1- 4} -alkyl acrylate copolymer; acrylonitrile isoprene rubber; styrene isoprene rubber; polyisoprene; natural rubber; epoxidized natural rubber; and mixtures thereof.

The preparation of nitrile rubber by the polymerization of the above monomers has been fully understood by those skilled in the art and described fully in the literature. Nitrile rubber that can be used for the purposes of the present invention is also commercially available, for example products from the product range of Perbunan® and Krynac® grades from Lanxess Germany GmbH.

Rubber with stabilizer disclosed above and especially stabilized nitrile rubber accident It demonstrates very good storage and color stability, positive processing performance and constant positive mechanical and dynamic performance.

After a long period of time, especially at higher temperatures, if the Mooney viscosity is as stable as possible, it provides good rubber storage stability.

Generally, the storage stability is determined by storing unvulcanized rubber at an elevated temperature (also known as hot air storage) for a specified period of time and determining the difference in Mooney viscosity before and after storage at this elevated temperature . Since the Mooney viscosity of rubber generally increases during hot air storage, the storage stability is expressed as the difference in Mooney viscosity after storage minus Mooney viscosity before storage. This will be demonstrated on the following examples of stabilized nitrile rubber: The stabilized rubber can be prepared according to the invention by contacting the stabilizer component with the rubber.

This incorporation can be achieved in various ways during (1) during the preparation of the rubber, including the polymerization and finishing of the rubber, the latter including coagulation and segregation, (2) one or more further chemistry after the preparation of the rubber In the conversion step, such as a metathesis reaction, a hydrogenation reaction or a homogeneous polymer reaction such as a graft, and/or (3) during the preparation of a vulcanizable mixture based on the nitrile rubber or during the nitrile rubber one or more times After further chemical conversion and before crosslinking.

The addition of ingredients in any of the above steps can be achieved by different means: ingredients (a), (b), (c) and (d) can be added separately. Different mixtures of the three ingredients can be combined. Whether added individually or in any type of combination, the three ingredients are usually used as a dispersion or emulsion.

Unless otherwise indicated, the percentages and other amounts mentioned in this specification are calculated by weight. The percentage is selected from any quoted range so that the sum reaches 100%.

The present invention is further described by examples, but it does not have any limited meaning.

Example 1

Antioxidant 1520 (16.67% w/w) and antioxidant 1076 (16.67% w/w) were added to a container and heated by high shear stirring. When the mixture melted, the p-cresol and dicyclopentadiene copolymer (16.67% w/w) was added. The mixture was heated to 115°C for 15 minutes and then cooled to 95°C. A mixture of oleic acid (3.34% w/w) and 50% strength aqueous potassium hydroxide solution (1.31% w/w) was added, and the mixture was stirred for 5 minutes. Hot water (45.07%) at 80°C was added at a rate of 6 liters/minute. When the remaining water to be added is 0.15% of the total water content, xanthan gum (0.08%) is sprinkled on the solution, and then the remaining water is added. The mixture was allowed to cool to 40°C, the biocide (Acticide (MBL) 0.20%) was added with stirring, and then the mixture was packaged for use or distribution as required.

The obtained antioxidant is a solid suspension in water, having a viscosity of 250-450cP and a pH value of 9.0-11.5, a particle size of d95%<3μm and a total solid content of 53-55%.

Example 2

Antioxidant 1520 (25% w/w) was added to a container and heated with high shear stirring. The copolymer of p-cresol and dicyclopentadiene (25% w/w) was added at 60°C. The mixture was heated to 115°C for 30 minutes and then cooled to 95°C. A mixture of oleic acid (3.34% w/w) and 50% strength aqueous potassium hydroxide solution (1.31% w/w) was added, and the mixture was stirred for 5 minutes. Hot water (45.07%) at 80°C was added at a rate of 6 liters/minute. When the remaining water to be added is 0.15% of the total water content, xanthan gum (0.08%) is sprinkled on the solution, and then the remaining water is added. The mixture It was allowed to cool to 40°C, the biocide (Acticide (MBL) 0.20%) was added with stirring, and then the mixture was packaged for use or distribution as required.

The obtained antioxidant is a solid suspension in water, having a viscosity of 400-600 cP and a pH value of 9.0-11.5, a particle size d 95%<3 μm and a total solid content of 53-55%.

Example 3

Antioxidant 1520 (12.5% w/w) was added to a container and heated by high shear stirring. At 60°C antioxidant 1076 (37.5% w/w) was added. The mixture was heated to 115°C for 30 minutes and then cooled to 95°C. A mixture of oleic acid (3.34% w/w) and 50% strength aqueous potassium hydroxide solution (1.31% w/w) was added, and the mixture was stirred for 5 minutes. Hot water (45.07%) at 80°C was added at a rate of 6 liters/minute. When the remaining water to be added is 0.15% of the total water content, xanthan gum (0.08%) is sprinkled on the solution, and then the remaining water is added. The mixture was allowed to cool to 40°C, the biocide (Acticide (MBL) 0.20%) was added with stirring, and then the mixture was packaged as required for use or distribution.

The resulting antioxidant is a solid suspension in water with a viscosity of 200-500 cP and a pH of 9.5-11.0, a particle size d 95%<2 μm and a total solids content of 53% to 55%.

Claims (21)

A stabilizer for an organic polymer mixture comprising one or more compounds from group (a), one or more compounds from group (b) and one or more compounds from group (c), wherein (a): (b): (c) The weight ratio is in the range of 5 to 30: 5 to 30: 5 to 30, (a), (b) and (c) are as follows: (a) The pair of formula I Copolymer of cresol and dicyclopentadiene;

Where n is an integer in the range from 1 to 10, (b) a sterically hindered phenol of formula II; and

Wherein R ¹ is a hydrogen group; linear or branched, saturated or unit or polyunsaturated, unsubstituted or substituted alkyl; saturated or unit or polyunsaturated carbocyclic or heterocyclic group Aryl; heteroaryl, arylalkyl, heteroarylalkyl, polyoxyalkylene ether; and R ² is the same or different and represents a linear or branched C ₁ -C ₆ alkyl or C ₅ -C ₆ cycloalkyl; (c) an alkylthiomethylphenol antioxidant of formula III;

R ³ is a linear or branched C ₁ -C ₁₄ alkyl group; and R ⁴ is a hydrogen group, a linear or branched, saturated or unit or polyunsaturated, unsubstituted or substituted alkane Group; saturated or unit or polyunsaturated carbocyclic or heterocyclic group; aryl; heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, Alkylthio or arylthio. The stabilizer according to item 1 of the patent application scope, wherein: the compound (a) is an L-type antioxidant; and the compound (c) is an antioxidant 1520. The stabilizer as described in item 1 of the patent application scope, wherein: compound (a) is an L-type antioxidant; compound (b) is an antioxidant 1076; and compound (c) is an antioxidant 1520. The stabilizer as described in item 1 of the patent application scope, wherein the weight ratio of (a):(b):(c) is 10:10:10. The stabilizer as described in item 1 of the patent application scope, wherein the weight ratio of (a):(b):(c) is 20:10:20. The stabilizer according to any one of items 1 to 5 of the patent application range, which contains an aqueous solution or dispersion of the stabilizer. The stabilizer as described in item 1 of the patent application scope, wherein the polyoxyalkylene ether is polyoxyethylene ether, polyoxypropylene ether or polyoxyethylene polyoxypropylene ether. A stabilizer for an organic polymer mixture comprising one or more compounds from group (a) and one or more compounds from group (c), wherein (a): (c) is in a weight ratio of 4 : Within the range of 1 to 1:1, (a) and (c) are as follows: (a) p-cresol and dicyclopentadiene copolymer of formula I;

Where n is an integer in the range from 1 to 10; and (c) an alkylthiomethylphenol antioxidant of formula III:

R ³ is a linear or branched C ₁ -C ₁₄ alkyl group; and R ⁴ is a hydrogen group, a linear or branched, saturated or unit or polyunsaturated, unsubstituted or substituted alkane Group; saturated or unit or polyunsaturated carbocyclic or heterocyclic group; aryl; heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, Alkylthio or arylthio. The stabilizer according to item 8 of the patent application scope, wherein the stabilizer comprises a compound from group (a) and a compound from group (c). The stabilizer as described in item 8 of the patent application scope, wherein the range is 3:1 to 1:1. The stabilizer as described in item 10 of the patent application scope, wherein the range is from 2:1 to 1:1. The stabilizer as described in item 11 of the patent application scope, wherein the scope is 1:1. A stabilizer for an organic polymer mixture comprising one or more compounds from group (b) and one or more compounds from group (c), wherein (b): (c) is in a weight ratio of 4 : Within the range of 1 to 1:1, (b) and (c) are as follows: (b) a sterically hindered phenol of formula II; and

Wherein R ¹ is a hydrogen group; linear or branched, saturated or unit or polyunsaturated, unsubstituted or substituted alkyl; saturated or unit or polyunsaturated carbocyclic or heterocyclic group Aryl; heteroaryl, arylalkyl, heteroarylalkyl, polyoxyalkylene ether; and R ² is the same or different and represents a linear or branched C ₁ -C ₆ alkyl or C ₅ -C ₆ cycloalkyl; (c) an alkylthiomethylphenol antioxidant of formula III;

R ³ is a linear or branched C ₁ -C ₁₄ alkyl group; and R ⁴ is a hydrogen group, a linear or branched, saturated or unit or polyunsaturated, unsubstituted or substituted alkane Group; saturated or unit or polyunsaturated carbocyclic or heterocyclic group; aryl; heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, Alkylthio or arylthio. The stabilizer according to item 13 of the patent application scope, wherein the stabilizer comprises a compound from group (b) and a compound from group (c). The stabilizer as described in item 13 of the patent application scope, wherein the range is 3:1 to 1:1. The stabilizer as described in item 15 of the patent application scope, wherein the range is 2:1 to 1:1. The stabilizer as described in item 16 of the patent application scope, wherein the scope is 1:1. The stabilizer according to any one of claims 13 to 17, further comprising a phosphite antioxidant. The stabilizer according to item 18 of the patent application scope, wherein the phosphite antioxidant is selected from the group consisting of tris(nonylphenyl) phosphite; tris(2,4-di-tert-butyl Phenyl) phosphite; and Other alkylaryl phosphites and their mixtures. The stabilizer as described in item 13 of the patent application range, wherein the polyoxyalkylene ether is polyoxyethylene ether, polyoxypropylene ether or polyoxyethylene polyoxypropylene ether. A method for preparing a stabilizer according to any one of items 1 to 6 of the patent application scope, which comprises the steps of: selecting a group selected from any one of the items 1 to 6 of the patent application scope A mixture of the compounds of (a), (b), (c) is heated to a temperature above 60°C to form a molten mixture; a surfactant is added to the molten mixture; hot water is added to the molten mixture to form An aqueous mixture; stirring the aqueous mixture; and optionally adding one or more further raw materials.